For a Solid-State Drive (SSD) system or other compact power system, a switching converter is employed to provide a DC (Direct current) voltage, and complete output discharge for the switching converter is needed during power cycling in order to start up the SSD system at a certain state. If there is any residential voltage bias on an output port of the switching converter during power cycling, the SSD system is under a risk to start up at an uncertain state which may cause a system issue. Conventional output discharge circuit employs a transistor to discharge an output voltage of the switching converter. However, when an input voltage is lost, there is not enough power to drive the transistor. As a result, the transistor may not work normally to discharge the output voltage of the switching converter completely, and the SSD system suffers a risk of uncertain state during start up.